The San Andreas fault as it looks from the air northwest of Bakersfield. Register file photo. MARK RIGHTMIRE, THE ORANGE COUNTY REGISTER

Graphics

A statewide warning system could sound the alarm – seconds to more than a minute – before a large earthquake under a new proposal by a state legislator.

Scientists would spend an estimated $80 million over five years to expand and upgrade the California Integrated Seismic Network under the bill, introduced Monday by state Sen. Alex Padilla, D-Pacoima.

In a news conference at Caltech to announce the bill, Padilla compared the proposed cost of the system to the $13 billion in damage caused by the magnitude 6.7 Northridge earthquake in 1994.

"We'll have an earthquake warning system, but will it be before or after the next Big One?" Padilla said. "I argue that it ought to be before."

The system would measure the quake's strength and direction, likely sending out warnings in a variety of ways, including on smartphones.

With such a system in place, people living closer to the epicenter of the quake in the state's large metropolitan areas might receive a few seconds' warning, those 160 miles away nearly 70 seconds – though at the farthest distances with the most warning, shaking might only be slight.

Anyone within 21 miles would be in a "blind zone," receiving no warning. Those 40 miles distant might get 10 seconds' warning.

But even a few seconds would be enough to "duck and cover," slow trains, reroute power supplies, or suspend construction work or surgery until the shaking stops.

"It all depends on where does the earthquake start relative to your location," said Egill Hauksson, a Caltech seismologist helping develop the network. "Say it started by the Salton Sea. You in Orange County are looking at a minute. But if the earthquake is right there on the Whittier fault, then you might be talking about a few seconds at most."

Simply stopping work or moving to a safer spot could potentially save lives.

"Factories handling difficult or dangerous chemicals may want to stop doing that for a few minutes," Hauksson said. "Construction workers may often be in dangerous places, where things may fall on them. If they get the warning, they may be able to move to a safe place."

The U.S. Geological Survey and Caltech operate about 300 seismic stations arrayed across Southern California, he said. About 100 of those would need to be upgraded and another 100 added to make a warning system function properly.

In Northern California, about 100 stations operated by USGS and UC Berkeley include up-to-date technology; 300 others would have to be upgraded, about 100 added.

In tests in the Los Angeles area, the existing system of sensors was able to warn operators of coming quakes. Scientists are working with selected users, such as utility companies, to test the system, he said.

How quickly the system could be completed would depend on legislative approval and funding sources, he said.

It also would depend on what the public considers acceptable: a more quickly built system that would give many false alarms, and miss some quakes but could improve over time, or a more reliable system that would take longer to construct.

"We're looking at a time range of two to three years," Hauksson said.

The proposal comes three weeks after scientists from Caltech, along with researchers in Japan, published a study showing that a large earthquake on the San Andreas fault could cause shaking along the length of the state, from the Salton Sea to as far north as San Francisco.

Related Links

User Agreement

Keep it civil and stay on topic. No profanity, vulgarity, racial
slurs or personal attacks. People who harass others or joke about
tragedies will be blocked. By posting your comment, you agree to
allow Orange County Register Communications, Inc. the right to
republish your name and comment in additional Register publications
without any notification or payment.